Catheters may be used for introducing and removing fluids in and from various vessels and cavities throughout the body. Central venous catheters, for example, are generally placed in four common locations within the chest and/or in the femoral vessels. They may be placed, for example, in either the right or left subclavian vein or in the right or left internal jugular vein. Such catheters use a guide wire to properly place the catheter in the catheterized area.
Using landmarks, vessels are identified and may be cannulated by first aspirating the vessel with a long hollow needle, which may be attached to a syringe or other aspirating device to ensure that the vessel has been properly located. When the vessel has been properly located and aspirated, if a syringe is used, the syringe is disconnected and a thin guide wire is passed through the needle into the hollow passage, or lumen, of the vessel. Other introducers allow the guide wire to pass through the syringe or device without removing the device from the needle. The needle or other introducer device is then removed, leaving one end of the guide wire within the vessel. The other end of the guide wire projects beyond the surface of the skin.
At this point, the simplest method of catheter placement is to pass a catheter into the vessel directly over the guide wire. The guide wire is then removed, leaving the catheter in position within the vessel. The catheter as placed can then function in various applications such as infusion, perfusion, hemodialysis and the like.
The guide wires used for such procedures are generally spring wires, which typically have a curved J-shaped tip. The nature of the spring wire, which is typically constructed from a memory alloy, causes the tip to return to the J-shape after applied stress is removed. Therefore, in order to slide the tip through the device and to keep the wire from bending back on itself while entering the patient, such wires are typically introduced through a straightening device. The guide wire has a relatively long length. For convenience, the wire is typically packaged and used as a coil. The coils generally have plastic clips which help to hold the coil together for handling. In addition, the coils can be packaged in protective storage tubes which also may use clips to hold the tubes in a coiled configuration.
The mechanical difficulties encountered by a physician or other medical personnel using such guide wires typically are the result of the need to use two hands to handle the guide wire and to operate an advancing apparatus while inserting the guide wire through the needle into the patient. Various prior art devices are directed to simplifying the advancing and insertion procedure, including a plastic cone having a hole at the tip of the cone for passing the guide wire through the hole into the introducer hub, and a shuttling device as described in U.S. Pat. No. 4,713,059. These devices, while assisting in advancing the wire through the introducer and guiding the wire into the needle, require two hands to operate.
Guide wires typically range in diameter from a relatively large 0.045 in to a relatively very small 0.018 in. Difficulty is usually encountered in controllably inserting the distal tip of at least the very small diameter size guide wire into the proximal opening of the introducer or syringe or proximal catheter fitting for vascular insertion into the patient.
Other solutions to the problem of two-handed guide wire advancing and straightening include a device as described in U.S. Pat. No. 5,125,906, which teaches a trigger-like handle with a clip which can be attached to a guide wire feeding tube or coil. The device has a frustoconical, tapered, distal end portion. The device is held with the fingers coiled around the trigger handle and the guide wire is fed into the device through a proximal opening, slid across a flat surface by the thumb and through the distal end portion into a syringe or needle introducer. A modified version of the device is disclosed in U.S. Pat. No. 5,484,419, which includes an additional, separate conical end fitting which can be placed over the end portion to help feed the guide wire into the needle and which has an arched underneath surface for facilitating handling of the device to enhance sliding of the guide wire over a flat top surface of the device. One problem with these guide wire advancers is the inability of the physician to accurately determine whether and how far the guide wire is advancing into the vessel using the thumb alone.
A virtually identical device is described in U.S. Pat. No. 5,507,300, which provides a rubber band along the wire guide to allow the physician to stop the insertion of the guide wire without letting the guide wire slip along the guide.
U.S. Pat. No. 5,366,444 discloses a guide wire advancer which provides a head with a guide opening, a discharge opening, and an open platform therebetween. A guide wire is advanced over the platform with a thumb, with a forefinger engaging a depression on an underside of the platform.
Other devices disclosed by U.S. Pat. Nos. 4,860,757, 4,917,094, 5,273,042, 5,438,993, and 5,448,993 describe a guide wire housed in a tube with apertures or a conical straightener as described above with a thumb opening cut into the conical portion. A physician's thumb fits into the aperture to engage the guide wire to advance or retract the guide wire through the tube.
A device disclosed by U.S. Pat. No. 6,551,281, invented by the present inventor, describes a guide wire advancer with an open central portion that flexibly connects a proximal portion and a distal portion through which a guide wire is contained. A physician grasps the guide wire between thumb and forefinger at the central portion and feeds the guide wire through the distal portion. Alternatively, while grasping the guide wire between the thumb and forefinger as described above, the physician advances the guide wire distally, compressing the open central portion by disposing the proximal portion toward the distal portion. Upon release of the guide wire and the advancer, the open central portion reverts to its original shape. Friction between the guide wire and the blood vessel into which the guide wire has been inserted keeps the guide wire from being pulled out of the vessel.
The above-described guide wire straighteners allow guide wires to be inserted in limited ways. However, different physicians have different preferences on techniques to be employed to advance a guide wire. Each of the guide wire advancers described above may require a physician to insert a guide wire using a technique or method with which he or she is uncomfortable or unfamiliar, risking potential injury to the patient during insertion.
Therefore, there is a need in the art for a guide wire advancer and/or straightening device which is alternatively operable through at least one of several alternate methods so that the physician inserting the guide wire has the option of using the method with which he/she he or she is most comfortable using.